1. Field of the Invention
This invention relates to a weighing and packaging system. More specifically, the present invention relates to a weighing and packaging system for weighing and packaging articles.
2. Background Information
There are many kinds of articles of which a predetermined weight or amount is packed in a bag, circulated and sold. Examples of such good include confectionery, fruit and vegetables, daily dishes, dried noodle, and processed food. In general, such articles are first weighed by a weighing device such that a predetermined amount of the articles is taken, and then put in a bag using a packaging device. A system for carrying out weighing and packaging of such articles mainly includes a weighing device and a packaging device. The weighing device performs a combination calculation that calculates combination of two or more weights or numbers of articles to obtain a predetermined weight or number of articles. The packaging device produces a bag from a film and puts into the bag the articles, which has been adjusted to be the predetermined amount by the weighing device.
One example of such system for weighing and packaging (hereinafter referred to as a weighing and packaging system) and devices used for previous and subsequent processes thereof are shown in FIG. 1. In this system, articles are first conveyed to a position above a weighing device 110 by a conveyer device 101. Then the articles are placed on a dispersion feeder 111 and dispersed radially by virtue of the vibration of the dispersion feeder 111. The articles are supplied to a plurality of pool hoppers 113, and temporally pooled therein. The pool hoppers 113 are circumferentially disposed via radially-extending troughs 112 connected to the dispersion feeder 111. After that, the articles are put into weighing hoppers 114, which are disposed below the respective pool hoppers 113. The weight of the articles put in the weighing hoppers 114 is measured by a load cell (a weight detection device) provided with each of the weighing hopper 114. Then, calculation is performed to determine what combination of weighing hoppers 114 should be discharged to obtain a combination weight or amount within an allowable limit, based on the measured weight of amount of articles in each weighing hopper 114. Based on this calculation, the designated weighing hoppers 114 discharge the articles into a discharging shoot 115, as seen in FIG. 2.
On the other hand, a packaging device 120 disposed below the weighing device 110 is a device which fills a bag with the articles discharged from the weighing device 110 while producing bags. The main structure of the packaging device 120 is shown in FIG. 3. This structure is a so-called vertical type pillow packaging device. In this packaging device 120, a sheet type film Fm, which is supplied from a film roll 128 shown in FIG. 1, is formed into a cylindrical shape by a former 121 and a tubular portion 122. The film is then sent downwardly by a pull-down belt mechanism 125. Then, the overlapping vertical edges of the cylindrically formed film Fmc, are heat-sealed by using a vertical seal 123. After the weighed articles are filled in the cylindrical film Fmc through the tubular portion 122, an upper end of a bag and a lower end of a subsequent bag are transversely sealed at the same time by a transverse sealing mechanism 124, which is disposed below the tubular portion 122. At the same time, the center of the transversely sealed portion is cut by a cutter attached to the transverse sealing mechanism 124.
As seen in FIG. 3, a bag B which is filled with the articles is transferred to a conveyer 130 through an inclined guiding plate 129, and conveyed to a weight checker 140, which is used for a subsequent weight-checking process.
In the above-mentioned weighing and packaging system, bags of a predetermined size are automatically manufactured so that articles may be sequentially packaged during normal operation. In order to synchronize the timing of discharging the articles whose weight have been measured by the weighing device with the timing of packaging the articles by the packaging device, a timing signal, which is an ON/OFF signal, is exchanged between controllers of the both devices. Also, a system is present which transmits an error signal, which is an ON/OFF signal, from the controller of the weighing device to the controller of the packaging device when an error is detected in the weighing device.
However, the weighing device and the packaging device are separate devices having different functions. Therefore, no consideration has been made to make the two devices work together except for the exchange of signals such as timing signals and error signals, which is the minimum requirement for both devices to perform normal operation.
When the measurement by the weight hoppers has become inaccurate due to debris from articles attached to the weight hoppers and consequently defective products are detected one after another at the weight checker in the subsequent process, or when the kind of articles has been changed, it is necessary to carry out a zero point calibrating process while no articles are present in the weighing hoppers. To do so, in order to force discharge of the articles from each of the weighing hoppers, the operation of the packaging device normally needs to be stopped. An inconstant weight or number of articles discharged from the weight hoppers has to be put into bags somehow. This operation has been conventionally performed manually by an operator. Specifically, the packaging device is stopped in a state in which there is a bag whose upper end is unsealed. Then articles discharged during the zero point calibrating process is put in the bag and the upper end of the bag is manually sealed, while checking the quantity of the articles in the bag.
Also, when the calculation for combination cannot be performed because of an introduction of different kinds of articles or lack of articles supplied to a weighting device, it is necessary to perform an all-drain process by which articles in all of the weighing hoppers are discharged. In that process, a bag of normal size (hereinafter referred to as a xe2x80x98one-bagxe2x80x99) or a bag having a length twice as long as that of a normal size bag (hereinafter referred to as a xe2x80x98double-bagxe2x80x99) has been conventionally manufactured to allow all the articles discharged in the all-drain process to be put in the bag regardless of the quantity of the articles discharged. Accordingly, if the process is carried out with a double-bag when a one-bag would have been sufficient, a waste of film would result. Conversely, if the process is carried out with a one-bag when a double-bag was in fact necessary to accommodate all the discharged articles, the bag cannot be sealed because of the overstuffing of the articles.
In view of the above, there exists a need for dental instrument which overcomes the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
One of the objects of the present invention is to reduce the burden on an operator and/or time required in performing processes such as the zero point calibrating process and the all-drain process with the weighing device, by coordinating processes of the weighing device with processes of the packaging device. In this manner, the present invention makes the operation of the packaging device efficient and accurate.
According to one aspect of the present invention, a weighing and packaging system includes a weighing device, a packaging device, and a controlling device. The weighing device is adapted to weigh articles and generate weight data of the articles. The packaging device is adapted to produce bags from a film, and package in the bags the articles which have been weighed in the weighing device. The controlling device determines a size of the bags to be produced by the packaging device based on quantity data. The quantity data is calculated from the weight data of the articles. The controlling device sends the size data to the packaging device.
Preferably, the weighing device has a plurality of weighing hoppers for receiving articles. Also, the weighing device carries out a combination operations by selecting a combination of the weighing hoppers based on the weight data of the articles in the weighing hoppers such that a total quantity of the articles in the combination of weighing hoppers is within a predetermined range, and discharges the articles in the combination of weighing hoppers.
Preferably, the controlling device performs a zero point calibrating process. The controlling device during the zero point calibrating process designates which of the weighing hoppers should be emptied and commands a discharge of the articles in the designated weighing hopper. In the mean time, the controlling device determines the size of a bag to be produced by the packaging device based on the quantity data of the articles to be discharged.
Preferably, the controlling device controlling device performs an all-drain process in which the articles in all of said weighing device are discharged. The controlling device during the all-drain process commands a discharge of articles in all of the weighing hoppers. In the mean time, the controlling device determines the size of a bag to be produced by the packaging device based on the quality data of the articles to be discharged.
Preferably, the controlling device performs an error process in which articles in an error weighing hopper are discharged. The controlling device during the error process designates the error weighing hopper and commands a discharge of the articles in the error weighing hopper. In the mean time the controlling device determines the size of a bag to be produced by the packaging device based on the quantity data of the articles to be discharged.
Preferably, the error weighing hopper is a weighing hopper that contains articles beyond the predetermined range.
Preferably, the controlling device determines the size of a bag to be produced in the packaging device based on a target quantity. The target quantity is inputted by an operator.
Preferably, the weighing device has a plurality of weighing hoppers for receiving the articles. The weighing device carries out combination operations based on the weight data of the articles put in the weighing hoppers, selects a combination of the weighing hoppers so that a total quantity of the articles in the combination of weighing hoppers is within a predetermined range including the target quantity, and discharges the articles in the combination of weighing hoppers.
Preferably, the packaging device is adapted to form a film into a cylindrically shaped bag aligned in a substantially vertical direction and having an upper opening, and to seal the upper opening after the articles are filled in the bag. The controlling device determines the vertical length of the bag based on the quantity data.
Preferably, the controlling device includes a first controlling part and a second controlling part. The first controlling part controls the weighing device, whereas the second controlling part controls the packaging device. The quantity data is transmitted from the first control part to the second control part.
Preferably, the quantity data is weight data.
Preferably, the quantity data is volume data calculated based on the weight data and a specific gravity of the articles.
Preferably, the total quantity of the articles is configured in terms of the weight of the articles.
Preferably, the total quantity of the articles is configured in terms of the number of the articles.
According to another aspect of the present invention, a weighing and packaging system includes a weighing device, a packaging device, and a controlling device. The weighing device is adapted to weigh articles and generate weight data of the articles. The packaging device is adapted to produce bags from a film, and package in the bags the articles which have been weighed in the weighing device. The controlling device determines a size of the bags to be produced by the packaging device based on quantity data. The quantity data is calculated from the weight data of the articles. The controlling device sends the size data to the packaging device. The controlling device is arranged to configure the weighing and packaging system in either normal operation state or special operation state.
Preferably, the weighing device has a plurality of weighing hoppers for receiving the articles. The weighing device is arranged to carry out a combination operation while the weighing and packaging system is in said normal operation state. The weighing device during the combination operation selects a combination of the weighing hoppers based on the weight data of the articles in the weighing hoppers so that a total quantity of the articles in the combination of weighing hoppers is within a predetermined range. The weighing device then discharges the articles in the combination of weighing hoppers.
Preferably, the controlling device is arranged to carry out a zero point calibrating process while the weighing and packaging system is in the special operation state. The controlling device during the zero point calibrating process designates which of the weighing hoppers should be emptied, commands a discharge of the articles in said designated weighing hopper to empty said designated weighing hopper, and stores the weight of an empty weighing hopper as a zero point. In the mean time, the controlling device determines the size of a bag to be produced by the packaging device based on the quantity data of the articles to be discharged.
Preferably, the controlling device is arranged to carry out an all-drain process while the weighing and packaging system is in the special operation state. The controlling device during the all-drain process commands a discharge of articles in all of the weighing hoppers to discharge articles in all of the weighing device, and determines the size of a bag to be produced by the packaging device based on the quantity data of the articles to be discharged.
Preferably, the controlling device is arranged to start said all-drain process automatically as said weighing and packaging system meets a predetermined criterion.
Preferably, the controlling device is arranged to start the all-drain process every predetermined period of time.
Preferably, the controlling device is arranged to start an error process while the weighing and packaging system is in the special operation state. The controlling device during the error process articles designates an error weighing hopper, commands a discharge of the articles in the error weighing hopper to discharge articles in the error weighing hopper, and determines the size of a bag to be produced by the packaging device based on the quantity data of the articles to be discharged.
The controlling device is arranged to carry out an all-drain process while the weighing and packaging system is in the special operation state. The controlling device during the all-drain process commands a discharge of articles in all of the weighing hoppers to discharge articles in all of the weighing hoppers, and determines the number of bags having a predetermined size to be produced by the packaging device based on the quantity data of the articles to be discharged.